Welding apparatus



June 9, 1942. TuTTLE 2,286,028

WELDING APPARATUS Filed Jan. 30, 1942 as n Inventom Fr-anK BTUttIe,

by Wang/ 9% His Attorney- Patented June 9, 1942 2,288,028 WELDING APPARATUS Frank B. Tuttle, Schenectady, N. in, aesignor to General Electric Company, a corporation or New York Application January 30, 1942, Serial No. 428,886

8 Claims.

- My invention relates to apparatus for automatically controlling a plurality of arcs. It is particularly suited for controlling a plurality of welding arcs which may or may not be associated with one another in a common unit or welding head.-

When an arc is established between non-consuming electrodes, or electrodes that are conin the hydrogen atmosphere at a very slow rate,

and a plurality of closely spaced arcs are often employed in order to increase the welding speed of a head embodying a plurality of pairs of such refractory electrodes. My invention, however, is not limited to applications for controlling multiarc atomic hydrogen welding heads, since it is also applicable to other apparatus in which a plurality of arcs are employed singularly or as a group to perform a desired operation or operations. It may also be applied to the control of a plurality of arcs established between one or more electrodes that are consumed in the presence of an arc at a fairly rapid rate.

It is an object of my invention to provide control apparatus in which a single regulating means is employed for automatically controlling a plurality of arcs.

It is a further object oi my invention to provide a simplified control for positioning pairs of cooperating'electrodes relatively to one another in each of a plurality oi welding circuits in response to a characteristic determined by the are established between said cooperating electrodes in each of said welding circuits.

It is also an object oi? my invention to provide a single regulating means which is connected in a desired sequence for predetermined'intervals of time to control each of a plurality of pairs of electrodes and the are established therebetween independently of the-control exerted on others thereof by said regulating means.

Further objects of my invention will become apparentfrom a consideration of the simplified control diagrammatically represented in the accompanying drawing.

In accordance with the illustrated embodiment of my invention a single regulating means is employed for periodically controlling each of a plurality of welding arcs established between pairs 01' cooperating electrodes. This regulating means is periodically connected to be responsive to an arc condition in each welding circuit and to control each of the welding heads employed for-feeding the electrodes in said circuit relative to one another. The regulating means is provided with a control circuit which is common to each of the motor means of the welding heads for the pairs of electrodes and with an energizing or responsive circuit which is common to each of the welding arcs or the welding circuits in which said arcs are connected. A plurality of branch circuits from the energizing and control circuits of the regulating means are completed by a distributor means for predetermined intervals of time in a predetermined sequence to each of the welding circuits and the motor means of the welding heads corresponding thereto. Means are also provided for independently adjusting the response of the regulating means to one or more of the Welding arcs or the circuits in which said arcs are connected.

In the simplified arrangement illustrated in the drawing cooperating pairs of electrodes 10 and I l are connected in independent welding circults I2 and i3. These pairs of electrodes are fed toward and away from one another by electrically operated motor means It and 16. The motor means for each pair of electrodes forms part of a mechanism usually identified as a welding head, and in the present instance comprises two independent electric motors each of which is gear connected to feed rolls which engage each one of a pair of cooperating electrodes. Each pair of motors for each welding head is simultaneously controlled for feeding the electrodes toward and away from one another. Each of these motors is provided with two field windings, the arrangement being such that when a motor is energized through one field winding it rotatesv in one direction, and when energized through the other field winding it rotates in the opposite direction.

The operation oi the motor means of each welding head for each pair of electrodes is controlled by a single regulator is. This regulator is provided with a control circuit common to the motor means of each welding head and an energizing or sensitive circuit which is common to each of the welding circuits for these pairs of electrodes. A distributor I1 is employed for periodically connecting the control and energizing may be an adiustable speed electric motor or its equivalent.

The regulator It shown in'the drawing is a contact making volt meter having a pair 01 fixed uected through gearing "to a motor 28 which "connection 46 of regulator contacts 21 and 2! and a movable contact 28 which is biased to engage fixed contact 21- by means a spring. The energizing or sensi-' tive coil ll of this regulator controls the magnetization oi a'core 22 which in turn controls the position of an armature 22 carrying the movable contact 28 of the regulator.

The energizing or sensitive coil of the regulator I .10 isprovided with'energizing connections 24 and 2!. Connection '3! branches into conductors "and 21 to one oi each of the pairs of electrodes 1 lator I. to each or the welding heads and welding circuits associated therewith in a predetermined sequence for predetermined intervals of time;

With the distributor disks in the positions 11- lustrated in the drawing, the energizing or sensitive coil ll of regulator I6 is connected across the pair of electrodes ll through brushes 40 and segment 42 of disk 20. At the same time control i8 is connected through brushes BI and segment 52 of disk I! to the upper field windings of motor means l for the welding head which controls the feeding of electrodes H and control connection 41 of regulator is is connected through brushes so and segment 6| of disk II to the lower field windings oi motor means Ii. The regulator is thus connected to be responsive to the voltage across elec- II' and II, and connection 34 branches into connections including adjustable resistors 28 and It, brushes 44 and 4|, conductive segments 42 and 43 of disks and 2! and conductors 44 and 45 to the other of each of the pairs of electrodes l0 and 'l I. The adjustable resistors 38. and it make it possible to control independently the response ofthe regulator means to arcing conditions in the welding circuits of electrodes lfl'and H.

Control connections 46 and 41 of regulator l8 are common to each oi the motor means of the welding heads for pairs oi electrodes ll and II.- Connection 4i branches through conductors 48- and 49, brushes i0 and SI, segments 52 and 52 of disks 22 and i8 and conductors I4 and 55 to corresponding field connections 0! motor means 14 and II of the welding heads for pairs 01 electrodes Ill and II. Connection 4'I branches through conductors it and 51, brushes 58 and I9 and segments 64 and 6| 0! disks 22 and I8, and conductors 62 and '83 to the other corresponding field connections of motor means [4 and II. Control connections 48 and 4! of regulator it are respectively connected to its fixed contacts 21 and 28. The movable contact 29 of the regulator is connected through another control connection 64 to one side of the source of supply 65. The other side of this 'source of supply is connected through conductors 88 and 81 to the armatures of motor means l4 and II oi the welding heads for pairs-oi electrodes Il and l I.

Disks l8 to 22 01' the distributor l-l may be made a or an electrical insulating material, or have insulating segments extending along their peripheries from one end to the other of the conductive segments 4|, I3. 42, 43, Ill and I2 oi these disks so that when brushes 5!, II, 40, 4|, I and II leave these conductive segments, the circuits through these brushes are interrupted. The conductive segments ll, I2 and 42 01 distributor disks is, ill and 2'. are 180 in length and displaced 180 from the segments 43, 64 and i2 of distributor disks 2|, 22 and 22. Consequently, when circuits are completed through brushes 58, ii and 42 by segments 6|, Stand 42 ct disks l8. l9 and 22, circuits through brushes 4t, 62, and it are interrupted by being out of engagement with segments 42, GI and D2 of disks 2|, 22 and 22. As previously stated these circuits are made and interrupted periodically by the rotation of disks II to 23 through the agency or motor 2 gear.

connected therewith. Consequently, the distributor l1 periodically connects the single. resutrodes II or the arc established therebetween. When this voltage exceeds a predetermined value, the energizing or sensitive coil 3| oi the regulator closes its contacts 28 and 28 against the bias of spring 30 to complete a control circuit through the lower field windings 0! motor means l5 across the source of supply 65. This will cause the motor means to operate to iced the electrodes toward one another and thus decrease the separation 01 their arcing terminals. and the length 01 the arc and its voltage. Conversely, ii the voltage between electrodes ii is less than a predetermined value, a control circuit through contacts 21 and 29 of regulator l6 willconnect motor means Iii through .their upper field windings across the source of supply 65 and cause them to rotate in the opposite directions to separate electrodes I l until the desired arc length and voltage is obtained While the regulator is thus employed for controlling the adjustment of electrodes. II and the arc established therebetween. motor. means 14 for the welding head employed for feeding the pair of electrodes I0 is deenergized by the open circuits at brushes ill and 58 of the distributor l1. Furthermore, the branch 01 the energizing circuit from electrodes III to coil 3| oi regulator i6 is interrupted at brushes 4| 0! the distributor. As the disks of the distributor rotate thecircuits completed through brushes 59, ii and 40 are interrupted and the circuits through brushes 4i, 58 and 50 are completed, thus transferring the regulator from its control of the pair 01 electrodes l I to the control of the pair of electrodes Ill. The control of the pair of electrodes ID by the regulator is the same as that above described in connection with the control of the pair of electrodes ll. Thus, as the disks of the distributor rotate,

the regulator is eflective, first to control the pair of electrodes ll and then the pair oi electrodes I.

of time during which the regulator is e'flective for controlling the pairs of electrodes Ill and II is is, of course, apparent that by choosing segments of different lengths, or'by controlling the speed or motor 25, or by varying both of these factors, the regulator may be used for controlling one pair of electrodes for a diflerent interval of time than it is used for controlling the other pair 0! electrodes. Such differences in times 01 application oi. the regulator to the control 0! each pair oi electrodes may be desirable because of conditions peculiar to each pair oi electrodesor the welding circuits in which they are connected. For example, the power supplied .to one arc may be in the arrangement illustrated the intervalsgreaterthanthatsupplbdtoothersandtheconsequent greater electrode consumption may require more frequentand longer adiustment periods to obtain the control required.

Theadiustableresistorsfl and I9 makeit possible to adjust independently the of regulatoriitothearcingconditionsofeaohofthe pairs of electrodes i and ii. It is thus possible to adjust the regulator for-holding one voltage betweenthepairofelectmdes ibandadiflferent voltage between the pair of electrodes ll.

It is, of course, apparent that the simple contactmakingvoltmetertypeofregulator illustratedinthedrawingmaybereplacedbyother forms of regulators to voltage, current,energyorotber conditionof anarc or its circuit. For example, the electronic control and regulator shown in United States Letters Patent 2,175,017 of William D. Cockrell granted October 3, i939, and ed to theassignee of this invention may be employed. Furthermore, instead of employing a welding head wherein each of a tive for controlling each pair of electrodes and the are established therebetween.

Although only two pairs of electrodes have been illustrated in the drawing it is, of course, apparent that more than two pairs may be employed. For example, the control of this invention is ad'- mirably suitable for controlling the pairs oi electrodes of a multiarc welding head such as disclosed in United States Letters Patent 2,282,031 of James T. Catlett for Welding apparatus, granted May 5, 1942, and assigned to the assignee of this invention.

As previously stated, my invention is not limited to the control of a plurality of welding arcs,

pair of electrodes is individually controlled by its I own motor means, a motor means may be employed for controlling both of the electrodes of a pair through the agency of a mechanism such as shown in Fig. 'I of United States Letters Patent 1,946,305 of James '1'. Catlett granted Februaryfi, l934,andtotheassigneeofthis invention. Furthermore, a single motor may be employed for controlling the feeding of all the pairs of electrodes through the agency of a plurality of electromagnetmally operated clutches such as shown in United States letters Patent 1,701,372 of Frank P. Jefts granted February 5,' 1929,andtothel 8i8n e vention.

'rhemotormeansoftheweldingheads need not be electrical or mechanical means electrically conholled, since mechanical means mechanically controlledmay be employed by using a mechanical distributor for transferring a mechanical control connection of the regulator.

Furthermore. my invention may be applied to the control of arcs-established between one or more electrodes, such as are used in that form of welding known as metallic arc welding. Insuchcasethemotormeansofeach weldingheadmaybecettofeedoneorbothoi the electrodes at a rate commensurate with everageelectrode u v inthearo,andasingle regulator through the agency of a distributor wouldperiodicallycorrectthespeedofthe motor means for any pair of cooperating electrodes in accordance with variations of the are resultingfromdiflerencesinthefeedingrate and consumption rate of one or more of the electrodes. Other arrangements will occur to those skilled in this art.

It is also apparent that many modifications mayhemadeintheconstructionofthe distributor. For example, the six disks illustrated in thedrawingmaybereplacedbyasingledislr about whose periphery the conductive segments and brushes of the disks II to 23 are properly distributed. Furthermore, the conductive segments and brushes may be replaced by switches operatedbycamportionsononeormoredisks associatedtherewith. The speed of the distributor motor 26 may be suitably controlled, or the n between the motor and the switch ing mechanism of thedistributor may be suitably controlled, to accomplish any desired speed of operation which will determine the duration of theintervalsduringwhichthoregmatoriseflecsince it may be employed for controlling a plurality of arcs used for any purpose. Also as was pointed out above, it is not necessary that the pairs of electrodes be associated with one another in'th'e same piece of apparatus. It is possible to use the control of my invention for independent welding heads acting on different work parts.

Modifications of my invention will occur to those skilled in the art in view of the above description thereof. I aim, therefore, in the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus comprising a plurality of circuits in each of which is connected a pair of cooperat ing electrodes whose position relative to one another determines an electrical characteristic of its said circuit, a plurality of electrode feeding means each of which controls the relative position of one of said pairs of cooperating electrodes, regulating means responsive to departures from a desired electrical characteristic of any one of said circuits for operating said electrode feeding means associated therewith to re-establish said desired characteristic by the proper positioning of said pair of cooperating electrodes connected in said one of said circuits, and distributor means for connecting said regulating means to each of said circuits and said electrode feeding means associated therewith in a desired sequence for predetermined intervals of time.

2. Apparatus comprising a plurality of circuits in'each of which is connected a pair of cooperating electrodes whose position relative to one another determines an electrical characteristic of its said circuit, a plurality of, electrode feeding means each of which controls the relative position of one of said pairs of cooperating electrodes, regulating means responsive to departures from a desired electrical characteristic of any one of said circuits for'operating said electrode feeding means associated therewith to re-establish said desired characteristic by the proper positioning of said pair of cooperating electrodes connected in said one of said circuits, distributor means for connecting said regulating means to each of said circuits and said electrode feeding means associated therewith in a desired sequence for predetermined intervals of time, and means for independently adjusting the response of said regulating means to said electrical characteristic of one or more of said circuits. v

3. Welding apparatus comprising a plurality of welding circuits in each of which is connected a pair of cooperating electrodes whose position relative to one another determines an electrical characteristic of its said welding circuit, a plurality of motor means each of which controls the feeding oi one oi said pairs or cooperating electrodes relative to one another, regulating means responsive to departures from a predetermined desired characteristic "or anyone of said welding circuits'i'or operating said motor means associated therewith tore-establish said desired characteristic by properly positioning said cooperating electrodes connected in said one oi. said circuits, said regulating means having a control connection common to each of said motor means and an energizing connection common to each of said welding circuits, and distributor means for respectively connecting said energizing and said control connections of said regulating means to each one 01 said welding circuits and said motor means associated therewith in a desired-sequence for predetermined intervals of time.

4. Welding apparatus comprising a plurality of welding circuits in each ofwhich is connected a pair of cooperating electrodes whose position relative to one another determines an electrical characteristic of'its said welding circuit, a plurality of welding heads each of which is provided with electrically operated motor means for controllingthe relative positions of one 01' said pairs of cooperating electrodes, regulating means responsive to departures from a predetermined desired characteristic 01' any one of said welding circuits for operating said motor means of said i welding head associated therewith to re-establish said desired characteristic by the proper positioning of said cooperating electrodes relative to one another in said one of said welding circuits; said regulating means having a control circuit common to each of said motor means of said welding heads and an energizing circuit common to each of said welding circuits, a plurality of branch circuits from said control circuit and said energizing circuit 01' said regulating means .to each 01' said welding head motor means and said welding circuit associated therewith, and means for simultaneously connecting for predetermined time intervals in a predetermined sequence said control and energizing circuits of said regulating means to said branch circuits for each of said welding head motor means and said welding circuit associated therewith. v

5. Welding apparatus comprising a plurality of welding circuits in each of which is connected a pair of cooperating electrodes whose position relative to one another determines'an electrical characteristic 01' its said welding circuit, a plurality oi electrically controlled motor means each abscess of which controls the feeding of a pair of said cooperating electrodes relative to one another, regulating-means responsive to departures from a predetermined desired characteristic of any one oi said welding circuits for operating said motor means associated therewith to re-establish said desired characteristic by the proper positioning of said cooperating electrodes connected in said one of said welding circuits, said regulating means having a controi circuit commonto each of said motor means and an energizing circuit common to each oi said welding circuits, distributor means for respectively connecting said control and energizing circuits of said regulating means to each of said motor means and the welding circuit associated therewitlrin a desired sequence for predetermined intervaisoi time, and means for independently controlling the response 01' the energizing circuit of said regulating means to said electrical characteristic of one or more of said welding circuits.

6. Weldingapparatus comprising a plurality oi welding circuits in each of which is connected a pair of cooperating electrodes whose position relative to one another determines an electrical characteristic of its saidwelding circuit, a plurality of electric motor means each 01' which controls the feeding of a pair of said cooperating electrodes relative to'one another, regulating means responsive to departures from a predetermined desired voltage characteristic of any one oi said welding circuits for operating said electric motor means for said cooperating electrodes in said one of said welding circuits to reestablish said desired voltage characteristic by the proper positioning of said electrodes, said regulating means having an energizing circuit responsive to voltage variations and control circuits selectively energized in accordance with variations above or below apnedetermined value 01' voltage applied to said energizing circuit, a plurality or circuits branching to each oi said pairs of electrodes of ,said'welding circuitsdrom said energizing circuit of said regulating means, a plurality of circuits branching to each of said electric motor means from said control circuits of said regulating means, and means for completing i'or' predetermined time intervals in a predetermined sequence the branch circuits from said energizing and control circuits of said regulating means to each of said welding circuits and its corresponding motor means.

FRANK B. 

